Sex Differences in the Development of Anthracycline-Associated Heart Failure.

BACKGROUND: Female sex is frequently cited as a risk factor for anthracycline cardiotoxicity based on pediatric data, but the role of sex in the development of cardiotoxicity has not been clearly established in adults. OBJECTIVES: To assess the effect of female sex on the development of incident heart failure (HF) in adult patients treated with anthracyclines. METHODS: This was a retrospective cohort study of 1525 adult patients with no prior history of HF or cardiomyopathy who were treated with anthracyclines between 1992 and 2019. The primary outcome was new HF within 5 years of the first dose of anthracyclines. The effect of sex was assessed using Cox proportional hazards and competing risk models. RESULTS: Over a median (IQR) follow-up of 1.02 (0.30-3.01) years, 4.78% of patients developed HF (44 men and 29 women). Female sex was not associated with the primary outcome in a multivariable Cox proportional hazards model (HR 0.87; 95% CI 0.53-1.43; P = 0.58). Similar results were observed in a multivariable model accounting for the competing risk of death (HR 0.94; 95% CI 0.39-2.25; P = 0.88). Age, coronary artery disease and hematopoietic stem cell transplant were associated with the primary outcome in a multivariable Cox proportional hazards model. Age and body mass index were associated with the primary outcome in a multivariable competing risk model. CONCLUSIONS: In this large, single-center, retrospective cohort study, female sex was not associated with incident HF in adult patients treated with anthracyclines. CONDENSED ABSTRACT: Female sex is frequently cited as a risk factor for anthracycline cardiotoxicity based on pediatric data, but the role of sex in the development of cardiotoxicity has not been clearly established in adults. In this retrospective cohort study, we assessed the effect of female sex on the development of incident heart failure in adult patients treated with anthracyclines. Using Cox proportional hazards and competing risk regression models, we found that there was no association between female sex and heart failure after treatment with anthracyclines.

Systemic Markers of Lung Function and Forced Expiratory Volume in 1 Second Decline across Diverse Cohorts.

Rationale: Chronic obstructive pulmonary disease (COPD) is a complex disease characterized by airway obstruction and accelerated lung function decline. Our understanding of systemic protein biomarkers associated with COPD remains incomplete. Objectives: To determine what proteins and pathways are associated with impaired pulmonary function in a diverse population. Methods: We studied 6,722 participants across six cohort studies with both aptamer-based proteomic and spirometry data (4,566 predominantly White participants in a discovery analysis and 2,156 African American cohort participants in a validation). In linear regression models, we examined protein associations with baseline forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity (FVC). In linear mixed effects models, we investigated the associations of baseline protein levels with rate of FEV1 decline (ml/yr) in 2,777 participants with up to 7 years of follow-up spirometry. Results: We identified 254 proteins associated with FEV1 in our discovery analyses, with 80 proteins validated in the Jackson Heart Study. Novel validated protein associations include kallistatin serine protease inhibitor, growth differentiation factor 2, and tumor necrosis factor-like weak inducer of apoptosis (discovery ß = 0.0561, Q = 4.05 × 10-10; ß = 0.0421, Q = 1.12 × 10-3; and ß = 0.0358, Q = 1.67 × 10-3, respectively). In longitudinal analyses within cohorts with follow-up spirometry, we identified 15 proteins associated with FEV1 decline (Q < 0.05), including elafin leukocyte elastase inhibitor and mucin-associated TFF2 (trefoil factor 2; ß = -4.3 ml/yr, Q = 0.049; ß = -6.1 ml/yr, Q = 0.032, respectively). Pathways and processes highlighted by our study include aberrant extracellular matrix remodeling, enhanced innate immune response, dysregulation of angiogenesis, and coagulation. Conclusions: In this study, we identify and validate novel biomarkers and pathways associated with lung function traits in a racially diverse population. In addition, we identify novel protein markers associated with FEV1 decline. Several protein findings are supported by previously reported genetic signals, highlighting the plausibility of certain biologic pathways. These novel proteins might represent markers for risk stratification, as well as novel molecular targets for treatment of COPD.

Protein Markers of Diabetes Discovered in an African American Cohort.

Proteomics has been used to study type 2 diabetes, but the majority of available data are from White participants. Here, we extend prior work by analyzing a large cohort of self-identified African Americans in the Jackson Heart Study (n = 1,313). We found 325 proteins associated with incident diabetes after adjusting for age, sex, and sample batch (false discovery rate q < 0.05) measured using a single-stranded DNA aptamer affinity-based method on fasting plasma samples. A subset was independent of established markers of diabetes development pathways, such as adiposity, glycemia, and/or insulin resistance, suggesting potential novel biological processes associated with disease development. Thirty-six associations remained significant after additional adjustments for BMI, fasting plasma glucose, cholesterol levels, hypertension, statin use, and renal function. Twelve associations, including the top associations of complement factor H, formimidoyltransferase cyclodeaminase, serine/threonine-protein kinase 17B, and high-mobility group protein B1, were replicated in a meta-analysis of two self-identified White cohorts-the Framingham Heart Study and the Malmö Diet and Cancer Study-supporting the generalizability of these biomarkers. A selection of these diabetes-associated proteins also improved risk prediction. Thus, we uncovered both novel and broadly generalizable associations by studying a diverse population, providing a more complete understanding of the diabetes-associated proteome.

Multiomic Profiling in Black and White Populations Reveals Novel Candidate Pathways in Left Ventricular Hypertrophy and Incident Heart Failure Specific to Black Adults.

BACKGROUND: Increased left ventricular (LV) mass is associated with adverse cardiovascular events including heart failure (HF). Both increased LV mass and HF disproportionately affect Black individuals. To understand the underlying mechanisms, we undertook a proteomic screen in a Black cohort and compared the findings to results from a White cohort. METHODS: We measured 1305 plasma proteins using the SomaScan platform in 1772 Black participants (mean age, 56 years; 62% women) in JHS (Jackson Heart Study) with LV mass assessed by 2-dimensional echocardiography. Incident HF was assessed in 1600 participants. We then compared protein associations in JHS to those observed in White participants from FHS (Framingham Heart Study; mean age, 54 years; 56% women). RESULTS: In JHS, there were 110 proteins associated with LV mass and 13 proteins associated with incident HF hospitalization with false discovery rate <5% after multivariable adjustment. Several proteins showed expected associations with both LV mass and HF, including NT-proBNP (N-terminal pro-B-type natriuretic peptide; ß=0.04; P=2×10-8; hazard ratio, 1.48; P=0.0001). The strongest association with LV mass was novel: LKHA4 (leukotriene-A4 hydrolase; ß=0.05; P=5×10-15). This association was confirmed on an alternate proteomics platform and further supported by related metabolomic data. Fractalkine/CX3CL1 (C-X3-C Motif Chemokine Ligand 1) showed a novel association with incident HF (hazard ratio, 1.32; P=0.0002). While established biomarkers such as cystatin C and NT-proBNP showed consistent associations in Black and White individuals, LKHA4 and fractalkine were significantly different between the two groups. CONCLUSIONS: We identified several novel biological pathways specific to Black adults hypothesized to contribute to the pathophysiologic cascade of LV hypertrophy and incident HF including LKHA4 and fractalkine.

Genetic Architecture of the Cardiovascular Risk Proteome.

BACKGROUND: We recently identified 156 proteins in human plasma that were each associated with the net Framingham Cardiovascular Disease Risk Score using an aptamer-based proteomic platform in Framingham Heart Study Offspring participants. Here we hypothesized that performing genome-wide association studies and exome array analyses on the levels of each of these 156 proteins might identify genetic determinants of risk-associated circulating factors and provide insights into early cardiovascular pathophysiology. METHODS: We studied the association of genetic variants with the plasma levels of each of the 156 Framingham Cardiovascular Disease Risk Score-associated proteins using linear mixed-effects models in 2 population-based cohorts. We performed discovery analyses on plasma samples from 759 participants of the Framingham Heart Study Offspring cohort, an observational study of the offspring of the original Framingham Heart Study and their spouses, and validated these findings in plasma samples from 1421 participants of the MDCS (Malmö Diet and Cancer Study). To evaluate the utility of this strategy in identifying new biological pathways relevant to cardiovascular disease pathophysiology, we performed studies in a cell-model system to experimentally validate the functional significance of an especially novel genetic association with circulating apolipoprotein E levels. RESULTS: We identified 120 locus-protein associations in genome-wide analyses and 41 associations in exome array analyses, the majority of which have not been described previously. These loci explained up to 66% of interindividual plasma protein-level variation and, on average, accounted for 3 times the amount of variation explained by common clinical factors, such as age, sex, and diabetes mellitus status. We described overlap among many of these loci and cardiovascular disease genetic risk variants. Finally, we experimentally validated a novel association between circulating apolipoprotein E levels and the transcription factor phosphatase 1G. Knockdown of phosphatase 1G in a human liver cell model resulted in decreased apolipoprotein E transcription and apolipoprotein E protein levels in cultured supernatants. CONCLUSIONS: We identified dozens of novel genetic determinants of proteins associated with the Framingham Cardiovascular Disease Risk Score and experimentally validated a new role for phosphatase 1G in lipoprotein biology. Further, genome-wide and exome array data for each protein have been made publicly available as a resource for cardiovascular disease research.

Application of Large-Scale Aptamer-Based Proteomic Profiling to Planned Myocardial Infarctions.

BACKGROUND: Emerging proteomic technologies using novel affinity-based reagents allow for efficient multiplexing with high-sample throughput. To identify early biomarkers of myocardial injury, we recently applied an aptamer-based proteomic profiling platform that measures 1129 proteins to samples from patients undergoing septal alcohol ablation for hypertrophic cardiomyopathy, a human model of planned myocardial injury. Here, we examined the scalability of this approach using a markedly expanded platform to study a far broader range of human proteins in the context of myocardial injury. METHODS: We applied a highly multiplexed, expanded proteomic technique that uses single-stranded DNA aptamers to assay 4783 human proteins (4137 distinct human gene targets) to derivation and validation cohorts of planned myocardial injury, individuals with spontaneous myocardial infarction, and at-risk controls. RESULTS: We found 376 target proteins that significantly changed in the blood after planned myocardial injury in a derivation cohort (n=20; P<1.05E-05, 1-way repeated measures analysis of variance, Bonferroni threshold). Two hundred forty-seven of these proteins were validated in an independent planned myocardial injury cohort (n=15; P<1.33E-04, 1-way repeated measures analysis of variance); >90% were directionally consistent and reached nominal significance in the validation cohort. Among the validated proteins that were increased within 1 hour after planned myocardial injury, 29 were also elevated in patients with spontaneous myocardial infarction (n=63; P<6.17E-04). Many of the novel markers identified in our study are intracellular proteins not previously identified in the peripheral circulation or have functional roles relevant to myocardial injury. For example, the cardiac LIM protein, cysteine- and glycine-rich protein 3, is thought to mediate cardiac mechanotransduction and stress responses, whereas the mitochondrial ATP synthase F0 subunit component is a vasoactive peptide on its release from cells. Last, we performed aptamer-affinity enrichment coupled with mass spectrometry to technically verify aptamer specificity for a subset of the new biomarkers. CONCLUSIONS: Our results demonstrate the feasibility of large-scale aptamer multiplexing at a level that has not previously been reported and with sample throughput that greatly exceeds other existing proteomic methods. The expanded aptamer-based proteomic platform provides a unique opportunity for biomarker and pathway discovery after myocardial injury.

Metabolite Profiles Predict Acute Kidney Injury and Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: Acute kidney injury (AKI) occurs commonly after transcatheter aortic valve replacement (TAVR) and is associated with markedly increased postoperative mortality. We previously identified plasma metabolites predictive of incident chronic kidney disease, but whether metabolite profiles can identify those at risk of AKI is unknown. METHODS AND RESULTS: We performed liquid chromatography-mass spectrometry-based metabolite profiling on plasma from patients undergoing TAVR and subjects from the community-based Framingham Heart Study (N=2164). AKI was defined by using the Valve Academic Research Consortium-2 criteria. Of 44 patients (mean age 82±9 years, 52% female) undergoing TAVR, 22 (50%) had chronic kidney disease and 9 (20%) developed AKI. Of 85 metabolites profiled, we detected markedly concordant cross-sectional metabolic changes associated with chronic kidney disease in the hospital-based TAVR and Framingham Heart Study cohorts. Baseline levels of 5-adenosylhomocysteine predicted AKI after TAVR, despite adjustment for baseline glomerular filtration rate (odds ratio per 1-SD increase 5.97, 95% CI 1.62-22.0; P=0.007). Of the patients who had AKI, 6 (66.7%) subsequently died, compared with 3 (8.6%) deaths among those patients who did not develop AKI (P=0.0008) over a median follow-up of 7.8 months. 5-adenosylhomocysteine was predictive of all-cause mortality after TAVR (hazard ratio per 1-SD increase 2.96, 95% CI 1.33-6.58; P=0.008), independent of baseline glomerular filtration rate. CONCLUSIONS: In an elderly population with severe aortic stenosis undergoing TAVR, metabolite profiling improves the prediction of AKI. Given the multifactorial nature of AKI after TAVR, metabolite profiles may identify those patients with reduced renal reserve.

Five-year clinical and economic outcomes among patients with medically managed severe aortic stenosis: results from a Medicare claims analysis.

BACKGROUND: Patients with severe, symptomatic aortic stenosis, who do not undergo valve replacement surgery have a poor long-term prognosis. Limited data exist on the medical resource utilization and costs during the final stages of the disease. METHODS AND RESULTS: We used data from the 2003 Medicare 5% standard analytic files to identify patients with aortic stenosis and a recent hospitalization for heart failure, who did not undergo valve replacement surgery within the ensuing 2 calendar quarters. These patients (n=2150) were considered to have medically managed severe aortic stenosis and were tracked over 5 years to measure clinical outcomes, medical resource use, and costs (from the perspective of the Medicare Program). The mean age of the cohort was 82 years, 64% were female, and the estimated logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) (a measure of predicted mortality with cardiac surgery) was 17%. During 5 years of follow-up, overall mortality was 88.4% with a mean survival duration of 1.8 years. During this time period, patients experienced an average of 4.4 hospital admissions, 52% were admitted to skilled nursing care, and 28% were admitted to hospice care. The total 5-year costs were $63 844 per patient, whereas mean annual follow-up costs (excluding the index quarter) per year alive were $29 278. CONCLUSIONS: Elderly patients with severe aortic stenosis undergoing medical management have limited long-term survival and incur substantial costs to the Medicare Program. These results have important implications for policy makers interested in better understanding the cost-effectiveness of emerging treatment options such as transcatheter aortic valve replacement.

In-hospital and 1-year outcomes with drug-eluting versus bare metal stents in saphenous vein graft intervention: a report from the EVENT registry.

OBJECTIVES: To compare outcomes of patients receiving drug-eluting stents (DES) versus bare metal stents (BMS) during percutaneous coronary intervention (PCI) of saphenous vein bypass grafts (SVG). BACKGROUND: Long-term benefits of DES versus BMS are well established for native vessel PCI. Benefit in patients undergoing SVG intervention is less certain. We used data from a multicenter registry (evaluation of drug eluting stents and ischemic events, EVENT) to compare outcomes among patients treated with DES versus BMS 1-year following SVG interventions. METHODS: Between July 2004 and December 2007, 684 patients in EVENT underwent SVG PCI (515 DES only, 169 BMS only). The primary endpoint was a composite of death, myocardial infarction (MI), and target lesion revascularization between hospital discharge and 1-year follow-up. Propensity score stratification was used to adjust for differences between groups. RESULTS: Baseline demographic and clinical characteristics of patients treated with DES and BMS were similar. The DES group had fewer men and a higher prevalence of prior PCI. Patients receiving DES had less angiographic thrombus, less frequent use of embolic protection devices, greater total stent length, and smaller maximum stent diameters. Unadjusted outcomes between discharge and 1-year follow-up did not differ between the groups. After risk adjustment, the primary outcome was less frequent among patients treated with DES (adjusted HR = 0.48, 95% CI = 0.27-0.84, P < 0.01) with similar relative benefits across the individual endpoints. CONCLUSIONS: Among patients undergoing SVG PCI in a "real world" registry analyzed using propensity score stratification, treatment with DES compared with BMS was associated with reduced MACE at 1 year following PCI.

Incidence and clinical outcome of minor surgery in the year after drug-eluting stent implantation: results from the Evaluation of Drug-Eluting Stents and Ischemic Events Registry.

BACKGROUND: The aim of the study was to describe the incidence and consequences of minor surgery after drug-eluting stent (DES) implantation. METHODS: The Evaluation of Drug-Eluting Stents and Ischemic Events (EVENT) Registry prospectively enrolled unselected patients undergoing percutaneous coronary intervention at 47 US centers between July 2004 and December 2007. We examined 8,323 patients who received a DES in EVENT to determine the frequencies of minor surgery and postoperative adverse events. RESULTS: Minor surgery (defined as procedures not requiring a major surgical incision) was performed in 164 (2.0%) of 8,323 patients <1 year after stenting, as follows: pacemaker/defibrillator implantation (46%), eye surgery (17%), orthopedic (9%), dermatologic (8%), endovascular (6%), and gastrointestinal procedures (5%). Compared with patients who did not undergo minor surgery, those who did were older, had more comorbidities, had more extensive coronary disease, and were more likely to have received warfarin after stenting. Only 1 (0.6%, 95% CI 0.0%-3.4%) of 164 patients had an event (stent thrombosis causing myocardial infarction) during the first week after minor surgery; this rate was slightly higher than the background rate of ischemic events in the study population (exact mid P = .01). Clopidogrel use at 12 months was similar between patients who did and those who did not undergo minor surgery (65.2% vs 65.5%, P = .95). CONCLUSIONS: In the EVENT Registry, minor surgery was performed in 2% of patients in the first year after DES implantation. The risk of stent thrombosis during the first week after surgery was increased slightly compared with background rates, but the absolute event rate was low (0.6%).

Cross-sectional relations of multiple inflammatory biomarkers to peripheral arterial disease: The Framingham Offspring Study.

BACKGROUND: Emerging evidence suggests that different inflammatory biomarkers operate through distinct biologic mechanisms. We hypothesized that the relation to peripheral arterial disease (PAD) varies for individual markers. METHODS: In a community-based sample we measured 12 biomarkers including plasma CD40 ligand, fibrinogen, lipoprotein-associated phospholipase-A2 mass and activity, osteoprotegerin, P-selectin, and tumor necrosis factor receptor 2 (TNFR2); and serum C-reactive protein, intracellular adhesion molecule-1, interleukin-6, monocyte chemoattractant protein-1, and myeloperoxidase in Framingham Offspring Study participants (n=2800, 53% women, mean age 61 years). We examined the cross-sectional relation of the biomarker panel to PAD using (1) a global test of significance to determine whether at least one of 12 biomarkers was related to PAD using the TEST statement in the LOGISTIC procedure in SAS and (2) stepwise multivariable logistic regression with forward selection of markers with separate models for (1) ankle-brachial index (ABI) category (<0.9, 0.9-1.0, >1.0) and (2) presence of clinical PAD (intermittent claudication or lower extremity revascularization). RESULTS: The group of inflammatory biomarkers were significantly related to both ABI and clinical PAD (p=0.01 and p=0.02, respectively, multi-marker adjusted global significance test). Multivariable forward elimination regression retained interleukin-6 and TNFR2 as significantly associated with PAD. For one standard deviation change in interleukin-6 and TNFR2 concentrations, there was a 1.21 (p=0.005) and 1.19 (p=0.009) increased odds of a change in ABI level respectively. Similar results were observed for clinical PAD. CONCLUSION: Interleukin-6 and TNFR2 were significantly associated with PAD independent of established risk factors and each other, suggesting that each marker represents a distinct biologic pathway.

Relations of measures of endothelial function and kidney disease: the Framingham Heart Study.

BACKGROUND: Endothelial dysfunction is prevalent in individuals with end-stage renal disease. Whether endothelial dysfunction is present in patients with moderate chronic kidney disease (CKD) is uncertain. STUDY DESIGN: Cross-sectional study. SETTINGS & PARTICIPANTS: Brachial reactivity measurements were obtained during the seventh examination cycle in 2,818 (diameter measurements) and 2,256 (flow measurements) Framingham Heart Study Offspring cohort participants (53% women; mean age, 61 +/- 9 years). PREDICTOR: Estimated glomerular filtration rate less than 60 mL/min/1.73 m(2) derived from creatinine- and cystatin C-based estimating equations; microalbuminuria status. OUTCOME: Brachial reactivity measurements (baseline brachial diameter, flow-mediated dilation, baseline and hyperemic mean flow). MEASUREMENTS: Linear regression models were used to model brachial measures as a function of CKD and microalbuminuria status. RESULTS: Overall, 7.3% (n = 206) of participants had CKD, and of 2,301 with urinary measurements, 10.0% (n = 230) had microalbuminuria. Brachial reactivity measures did not differ significantly by CKD status in either creatinine- or cystatin C-based equations in either age- and sex- or multivariable-adjusted models. In age- and sex-adjusted models, microalbuminuria was associated with decreased hyperemic mean flow (47.2 +/- 1.4 versus 51.4 +/- 0.5 mg/g; P = 0.005), but the association was not significant after multivariable adjustment (P = 0.09). LIMITATIONS: Predominantly white ambulatory cohort; results may not be generalizable to other ethnic groups or individuals with severe CKD. CONCLUSIONS: Endothelial dysfunction was not a major correlate of CKD in our sample.

Cross-sectional relations of digital vascular function to cardiovascular risk factors in the Framingham Heart Study.

BACKGROUND: Digital pulse amplitude augmentation in response to hyperemia is a novel measure of peripheral vasodilator function that depends partially on endothelium-derived nitric oxide. Baseline digital pulse amplitude reflects local peripheral arterial tone. The relation of digital pulse amplitude and digital hyperemic response to cardiovascular risk factors in the community is unknown. METHODS AND RESULTS: Using a fingertip peripheral arterial tonometry (PAT) device, we measured digital pulse amplitude in Framingham Third Generation Cohort participants (n=1957; mean age, 40+/-9 years; 49% women) at baseline and in 30-second intervals for 4 minutes during reactive hyperemia induced by 5-minute forearm cuff occlusion. To evaluate the vascular response in relation to baseline, adjusting for systemic effects and skewed data, we expressed the hyperemic response (called the PAT ratio) as the natural logarithm of the ratio of postdeflation to baseline pulse amplitude in the hyperemic finger divided by the same ratio in the contralateral finger that served as control. The relation of the PAT ratio to cardiovascular risk factors was strongest in the 90- to 120-second postdeflation interval (overall model R(2)=0.159). In stepwise multivariable linear regression models, male sex, body mass index, ratio of total to high-density lipoprotein cholesterol, diabetes mellitus, smoking, and lipid-lowering treatment were inversely related to PAT ratio, whereas increasing age was positively related to PAT ratio (all P<0.01). CONCLUSIONS: Reactive hyperemia produced a time-dependent increase in fingertip pulse amplitude. Digital vasodilator function is related to multiple traditional and metabolic cardiovascular risk factors. Our findings support further investigations to define the clinical utility and predictive value of digital pulse amplitude.

Prevalence and prognostic impact of subclinical cardiovascular disease in individuals with the metabolic syndrome and diabetes.

Data are limited regarding prevalence and prognostic significance of subclinical cardiovascular disease (CVD) in individuals with metabolic syndrome (MetS). We investigated prevalence of subclinical CVD in 1,945 Framingham Offspring Study participants (mean age 58 years; 59% women) using electrocardiography, echocardiography, carotid ultrasound, ankle-brachial blood pressure, and urinary albumin excretion. We prospectively evaluated the incidence of CVD associated with MetS and diabetes according to presence versus absence of subclinical disease. Cross-sectionally, 51% of 581 participants with MetS had subclinical disease in at least one test, a frequency higher than individuals without MetS (multivariable-adjusted odds ratio 2.06 [95% CI 1.67-2.55]; P < 0.0001). On follow-up (mean 7.2 years), 139 individuals developed overt CVD, including 59 with MetS (10.2%). Overall, MetS was associated with increased CVD risk (multivariable-adjusted hazards ratio [HR] 1.61 [95% CI 1.12-2.33]). Participants with MetS and subclinical disease experienced increased risk of overt CVD (2.67 [1.62-4.41] compared with those without MetS, diabetes, or subclinical disease), whereas the association of MetS with CVD risk was attenuated in absence of subclinical disease (HR 1.59 [95% CI 0.87-2.90]). A similar attenuation of CVD risk in absence of subclinical disease was observed also for diabetes. Subclinical disease was a significant predictor of overt CVD in participants without MetS or diabetes (1.93 [1.15-3.24]). In our community-based sample, individuals with MetS have a high prevalence of subclinical atherosclerosis that likely contributes to the increased risk of overt CVD associated with the condition.

Pulse pressure and risk of new-onset atrial fibrillation.

CONTEXT: Atrial fibrillation (AF) is responsible for considerable morbidity and mortality, making identification of modifiable risk factors a priority. Increased pulse pressure, a reflection of aortic stiffness, increases cardiac load and may increase AF risk. OBJECTIVE: To examine relations between pulse pressure and incident AF. DESIGN, SETTING, AND PARTICIPANTS: Prospective, community-based observational cohort in Framingham, Mass, including 5331 Framingham Heart Study participants aged 35 years and older and initially free from AF (median age, 57 years; 55% women). MAIN OUTCOME MEASURES: Incident AF. RESULTS: AF developed in 698 participants (13.1%) a median of 12 years after pulse pressure assessment. Cumulative 20-year AF incidence rates were 5.6% for pulse pressure of 40 mm Hg or less (25th percentile) and 23.3% for pulse pressure greater than 61 mm Hg (75th percentile). In models adjusted for age, sex, baseline and time-dependent change in mean arterial pressure, and clinical risk factors for AF (body mass index, smoking, valvular disease, diabetes, electrocardiographic left ventricular hypertrophy, hypertension treatment, and prevalent myocardial infarction or heart failure), pulse pressure was associated with increased risk for AF (adjusted hazard ratio [HR], 1.26 per 20-mm Hg increment; 95% confidence interval [CI], 1.12-1.43; P<.001). In contrast, mean arterial pressure was unrelated to incident AF (adjusted HR, 0.96 per 10-mm Hg increment; 95% CI, 0.88-1.05; P = .39). Systolic pressure was related to AF (HR, 1.14 per 20-mm Hg increment; 95% CI, 1.04-1.25; P = .006); however, if diastolic pressure was added, model fit improved and the diastolic relation was inverse (adjusted HR, 0.87 per 10-mm Hg increment; 95% CI, 0.78-0.96; P = .01), consistent with a pulse pressure effect. Among patients with interpretable echocardiographic images, the association between pulse pressure and AF persisted in models that adjusted for baseline left atrial dimension, left ventricular mass, and left ventricular fractional shortening (adjusted HR, 1.23; 95% CI, 1.09-1.39; P = .001). CONCLUSION: Pulse pressure is an important risk factor for incident AF in a community-based sample. Further research is needed to determine whether interventions that reduce pulse pressure will limit the growing incidence of AF.

Common genetic variation at the endothelial nitric oxide synthase locus and relations to brachial artery vasodilator function in the community.

BACKGROUND: Sequence variants at the endothelial nitric oxide synthase (NOS3) locus have been associated with endothelial function measures, but replication has been limited. METHODS AND RESULTS: In reference pedigrees, we characterized linkage disequilibrium structure at the NOS3 locus using 33 common single nucleotide polymorphisms (SNPs). Eighteen SNPs that capture underlying common variation were genotyped in unrelated Framingham Heart Study participants (49.5% women; mean age, 62 years) with measured brachial artery flow-mediated dilation (n=1446) or hyperemic flow velocity (n=1043). Within 3 defined blocks of strong linkage disequilibrium that spanned NOS3, 11 SNPs captured >80% of common haplotypic variation. Among men, there were nominally significant associations between 8 NOS3 SNPs (minimum P=0.002) and between haplotypes (minimum P=0.002) and either flow-mediated dilation or hyperemic flow velocity. In women, we did not observe significant associations between NOS3 SNPs or haplotypes and endothelial function measures. To correct for multiple testing, we constructed 1000 bootstrapped null data sets and found that empirical probability values exceeded 0.05 for both phenotypes. CONCLUSIONS: A parsimonious set of SNPs captures common genetic variation at the NOS3 locus. A conservative interpretation of our results is that, accounting for multiple testing, we did not observe statistically significant relations between NOS3 sequence variants and endothelial function measures in either sex. The nominal associations of select NOS3 variants with endothelial function in men (unadjusted for multiple testing) should be viewed as hypothesis-generating observations and may merit testing in other cohorts and experimental designs.

Brachial artery vasodilator function and systemic inflammation in the Framingham Offspring Study.

BACKGROUND: In experimental studies, traditional risk factors and proinflammatory processes alter the regulatory functions of the vascular endothelium to promote atherosclerosis. These alterations include expression of leukocyte adhesion molecules and decreased bioavailability of endothelium-derived nitric oxide, an important regulator of vascular homeostasis and tone. The precise relations among risk factors, inflammation, and nitric oxide bioavailability remain uncertain. METHODS AND RESULTS: To test the hypothesis that inflammation impairs endothelial function in humans, we measured brachial artery flow-mediated dilation, reactive hyperemia, and serum concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), soluble intracellular adhesion molecule-1 (sICAM-1), and monocyte chemotactic protein-1 (MCP-1) in 2701 participants from the Framingham Study (mean age 61 years, 53% women). There were modest unadjusted inverse correlations between flow-mediated dilation and CRP, IL-6, and sICAM-1 (P<0.001 for all) that were rendered nonsignificant after accounting for traditional coronary risk factors. For reactive hyperemia, we observed inverse correlations with markers of inflammation in unadjusted models that were attenuated 57% to 74% after accounting for risk factors. However, partial correlations of CRP, IL-6, and sICAM-1 with reactive hyperemia remained significant. CONCLUSIONS: Our observations are consistent with the hypothesis that risk factors induce a state of inflammation that impairs vascular function. For flow-mediated dilation, we found no evidence that inflammation has additional effects beyond those attributable to traditional risk factors. The incremental contribution of CRP, IL-6, and sICAM-1 to reactive hyperemia above and beyond known risk factors suggests that systemic inflammation may contribute to impaired vasomotor function in forearm microvessels.

Kidney function is inversely associated with coronary artery calcification in men and women free of cardiovascular disease: the Framingham Heart Study.

BACKGROUND: Among patients with end-stage renal disease (ESRD), the risk of cardiovascular disease is 10 to 20 times higher than the general population. Adults with ESRD have increased coronary-artery calcification (CAC) detected by electron-beam computed tomography (EBCT). Because the risk of coronary heart disease is increased even at moderate declines in kidney function, we sought to test whether high CAC scores are seen among those with mild reductions in kidney function. METHODS: Men and women free of symptomatic cardiovascular disease underwent EBCT. Coronary calcium was quantified using the method described by Agatston. Renal function was estimated by glomerular filtration rate (GFR). Spearman correlation coefficients were used to test the association between GFR and CAC. RESULTS: Three hundred nineteen subjects (162 men/157 women), mean age 60, were included. Mean GFR was 86 +/- 23 mL/min/1.73 m2 (range 31-169; 10% with GFR <60 mL/min/1.73 m2). The median CAC scores by quartile of GFR were 85.9, 48.1, 7.9, and 2.7. Overall, the unadjusted correlation of GFR and CAC was -0.28 (P < 0.0001). This remained significant after adjustment for age and sex (-0.11, P < 0.05), and additionally after adjustment for body mass index (-0.11, P < 0.05), hypertension (-0.11, P < 0.05), or total cholesterol (-0.12, P= 0.04). A similar correlation was noted after multivariable adjustment (-0.10, P < 0.08). CONCLUSION: Mild declines in kidney function are associated with subclinical coronary artery calcification in a sample of subjects free of clinically apparent cardiovascular disease. This might help explain the increased risk of cardiovascular disease among individuals with renal dysfunction. Larger ongoing studies are needed to better quantify this finding.

Changes in arterial stiffness and wave reflection with advancing age in healthy men and women: the Framingham Heart Study.

With advancing age, arterial stiffness and wave reflections increase and elevate systolic and pulse pressures. An elevated central pulse pressure is generally ascribed to increased wave reflection and portends an unfavorable prognosis. Using arterial tonometry, we evaluated central (carotid-femoral) and peripheral (carotid-brachial) pulse wave velocity, amplitudes of forward and reflected pressure waves, and augmentation index in 188 men and 333 women in the Framingham Heart Study offspring cohort who were free of clinical cardiovascular disease, hypertension, diabetes, smoking within the past 12 months, dyslipidemia, and obesity. In multivariable linear regression models, advancing age was the predominant correlate of higher carotid-femoral pulse wave velocity; other correlates were higher mean arterial pressure, heart rate, and triglycerides and walk test before tonometry (model R2=0.512, P<0.001). A similar model was obtained for carotid-brachial pulse wave velocity (model R2=0.227, P<0.001), although the increase with advancing age was smaller. Owing to different relations of age to central and peripheral stiffness measures, carotid-femoral pulse wave velocity was lower than carotid-brachial pulse wave velocity before age 50 years but exceeded it thereafter, leading to reversal of the normal central-to-peripheral arterial stiffness gradient. In this healthy cohort with a minimal burden of cardiovascular disease risk factors, an age-related increase in aortic stiffness, as compared with peripheral arterial stiffness, was associated with increasing forward wave amplitude and pulse pressure and reversal of the arterial stiffness gradient. This phenomenon may facilitate forward transmission of potentially deleterious pressure pulsations into the periphery.

Clinical correlates and heritability of flow-mediated dilation in the community: the Framingham Heart Study.

BACKGROUND: Studies in selected samples have linked impaired endothelial function with cardiovascular disease and its risk factors. The clinical correlates and heritability of endothelial function in the community have not been described. METHODS AND RESULTS: We examined a measure of endothelial function, brachial artery flow-mediated dilation (FMD), expressed as both percent (FMD%) and actual dilation by ultrasound with the occlusion cuff below the elbow in 2883 Framingham Study participants (52.9% women; mean age, 61 years). A subset of 1096 participants performed a 6-minute walk test before FMD determination. Mean FMD% was 3.3+/-3.0% in women and 2.4+/-2.4% in men. In stepwise multivariable linear regression models, FMD% was inversely related to age, systolic blood pressure, body mass index (BMI), lipid-lowering medication, and smoking, whereas it was positively related to female gender, heart rate, and prior walk test. The estimated heritability of FMD% was 0.14. FMD actual dilation findings were similar, except that female sex and BMI were not significantly associated. CONCLUSIONS: Increasing age, systolic blood pressure, BMI, and smoking were associated with lower FMD% in our community-based sample, whereas prior exercise and increasing heart rate were associated with higher FMD%. The estimated heritability of FMD was modest. Future research will permit more complete characterization of the genetic and environmental determinants of endothelial function and its prognostic value in the community.